View source for 68-pounder 95 cwt

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{{redirect|68-pounder}}
{{Infobox Weapon
|name= 68-pounder smoothbore cannon
|image=[[File:68pdr smoothbore.jpg|300px]]
|caption=Replica 68-pounder on [[HMS Warrior (1860)|HMS ''Warrior'']].
|origin= {{UK}}
|type= [[Naval gun]]<br>[[Coastal artillery|Coast Defence gun]]
<!-- Type selection -->
|is_ranged=yes
|is_explosive=
|is_artillery=yes
|is_UK=yes
<!-- Service history -->
|service=1846 - 1921
|used_by=[[United Kingdom]]
|wars= [[Crimean War]]
<!-- Production history -->
|designer=William Dundas 
|design_date=
|manufacturer=[[Low Moor Iron Works]]
|production_date=1846 - 1861
|number=In excess of 2000
<!-- General specifications -->
|weight=95 [[Hundredweight|cwt]]
|length=
|part_length={{convert|10|ft|10|in|m|sigfig=4}}
|width=
|height=
|crew=9 – 18
<!-- Ranged weapon specifications --> 
| cartridge          = [[Round shot|Solid Shot]]<br>[[Shell (projectile)|Explosive Shell]]
| cartridge_weight   = {{convert|68|lb|kg|sigfig=4}}
| caliber            = {{convert|8.12|in|cm|sigfig=4}}
|action= 
|rate=
|velocity={{convert|1280|ft/s|m/s}}
|range= Approximately {{convert|3000|yd|m}}
|max_range={{convert|3620|yd|m}}
|sights= 
<!-- Artillery specifications -->
|breech=
|recoil=
|carriage=
|elevation=0 – 15 degrees
|traverse=
}}

The '''68-pounder cannon''' was an artillery piece designed and used by the British Armed Forces in the mid-19th century. The cannon was a [[smoothbore]] [[Muzzleloader|muzzle-loading]] weapon that weighed  {{convert|95|long cwt|kg|abbr=on}} and fired projectiles of {{convert|68|lb|kg|abbr=on}}.  Colonel William Dundas designed the gun in 1846 and it was cast the following year.  It entered service with the [[Royal Artillery]] and the [[Royal Navy]] and saw active service with both arms during the [[Crimean War]]. Over 2000 were made and it gained a reputation as the finest smoothbore cannon ever made.

The gun was produced at a time when new [[rifling|rifled]] and [[breech loading]] guns were beginning to make their mark on artillery.  At first the 68-pounder's reliability and power meant that it was retained even on new warships such as [[HMS Warrior (1860)|HMS ''Warrior'']]. Eventually new [[Rifled_Muzzle_Loader#Rifled_muzzle_loaders|rifled muzzle loaders]] made all smoothbore muzzle-loading guns obsolete, but the large surplus stocks of 68-pounders were given new life when converted to take rifled projectiles. The cannon remained in service and was not declared obsolete until 1921.

==Design==
The cannon was designed in response to the need for heavier weaponry as armour on [[ship of the line|ships of the line]] improved.<ref name=Nelson/>  Colonel William Dundas, the government's Inspector of Artillery between 1839 and 1852, designed the cannon in 1846.<ref name=Nelson/><ref>{{cite web|url=http://www.hmswarrior.org/ship/armament.htm|title=HMS Warrior - Armament|publisher=The Warrior Preservation Trust|accessdate=2010-05-08}}</ref>  It was cast by the [[Low Moor Iron Works]] in [[Bradford]] in 1847 and entered service soon after.<ref name=Nelson/>  Like [[Naval artillery in the Age of Sail|numerous cannon before it]], it was a [[cast iron]] [[smoothbore]] loaded [[Muzzleloader|from the muzzle]].<ref name=Hogg37>Hogg, p. 37</ref> The cannon was relatively cheap to produce – the [[Royal Commission on the Defence of the United Kingdom]] estimated that each cannon cost approximately £167.<ref name=Hogg25>Hogg, p. 25</ref> Over 2000 were cast before 1861<ref>Lambert, p. 99</ref> and its exceptional durability, range and accuracy earned it a reputation as the finest smoothbore cannon ever made.<ref name=Nelson>{{Cite sign|title=Guns of the Crimean War|url= |date=|medium=Interpretation Board|distributor=[[Royal Armouries]]|location=[[Fort Nelson, Hampshire]]}}</ref><ref name=Lambert82>Lambert, p. 82</ref>

==Operation==
The gun was a traditional muzzleloader; it needed to be loaded from the end of the barrel.<ref name=Cantwell21>Cantwell, p. 21</ref> Before it could be loaded the bore of the barrel was cleaned with a sponge, after which an explosive charge (gunpowder in a cloth bag) was rammed down into the breech.<ref name=Cantwell21/> This was followed by a projectile, often encased in wadding.<ref name=Winton30>Winton (1987), p. 30</ref> The gun was primed (using a metal spike inserted through the vent that pierced the charge), and fired using a percussion cap (which detonated the charge and forced the projectile out of the barrel).<ref name=Cantwell28>Cantwell, p. 28</ref>

With a {{convert|16|lb|kg|abbr=on}} powder charge (smaller charges were possible, but 16 lb was the maximum the barrel could withstand), the cannon fired a {{convert|68|lb|kg|abbr=on}} solid shot at a muzzle velocity of {{convert|1280|ft/s|m/s|abbr=on}}.<ref name=Winton30/>   The official weight of the shot was listed at 68 lbs but in reality this varied according to the material of the shot itself; cast iron shot weighed {{convert|67|lb|kg|abbr=on}}, wrought iron shot and steel shot weighed {{convert|72|lb|kg|abbr=on}}, and chilled steel weighed {{convert|68|lb|8|oz|kg|abbr=on}}.<ref name=Winton30/>  It was estimated that one 68-pound shot had the destructive power equivalent to five 32-pound shot.<ref name=Lambert82/><ref>Winton (1987), p. 29</ref>

[[Image:Cannon diagram.svg|thumb|150px|left|A muzzle-loaded cannon: 1) projectile (shot),  2) powder charge, 3) vent]]
The cannon could also fire explosive shells primed with {{convert|4|lb|kg|abbr=on}} of gunpowder.<ref name=Winton30/> These shells were fitted with simple [[Fuse (explosives)|fuses]] that were ignited by the flash of the charge – early wooden fuses were eventually replaced by more reliable fuses designed by Captain [[Edward Boxer]] in 1849.<ref name=Cantwell28/> The gun crew still had to gauge the best length of fuse for the range they were firing – ideally the shell should explode just before hitting its target.<ref name=Winton30/> To prevent the shell exploding in the barrel it was fitted with a [[sabot]] to ensure the fuse faced away from the charge.<ref name=Cantwell28/>  The cannon could also fire [[grapeshot]], [[Canister shot|case shot]] and molten iron shells (thin walled shells filled with molten iron).<ref>Lambert, pp. 86–87</ref>

The 68-pounder had an effective range of approximately {{convert|3000|yd|m|abbr=on}}, however at its maximum elevation of 15 degrees it had a maximum range of {{convert|3620|yd|m|abbr=on}}, a distance that the projectile would cover in 15 seconds.<ref name=Winton30/>  Although the cannon's barrel bore was {{convert|8.12|in|cm}}, both shot and shells were {{convert|7.92|in|cm}} in diameter.  This allowed a [[British ordnance terms#Windage|windage]] gap of {{convert|0.1|in|cm|abbr=on}} around the projectile; enough to aid the loading process, but not enough to seriously diffuse the explosive gasses.<ref name=Winton30/>  

On land a minimum crew of nine men (usually commanded by a [[non-commissioned officer]]) was required to fire the gun, which was normally mounted on a traversing gun carriage.<ref name=Cantwell21/> On board a ship the gun crew could be doubled to 18 men who needed to traverse the gun carriage by hand, using hand spikes and rope tackles.<ref name=Winton30/> The extra crew was on account of the fact that sailing ships usually only fired their cannon from one side of the deck.  In the unlikely event of both sides being in action at once, nine men would be detached to man the gun opposite.<ref name=Winton30/> In both cases the gun was elevated using wooden wedges driven under the breech of the barrel by brute force.<ref name=Winton30/><ref>Cantwell, p. 28</ref> It was aimed using an advanced hexagonal sighting mechanism marked with the elevation on one face and the gun's range (according to different weights of cartridge charges) on the other five faces.<ref>Winton (1987), p. 33</ref><ref>Cantwell, pp. 21, 28</ref>

==Service==
The cannon was put to use both on land and at sea.<ref name=Nelson/>   It was fitted to numerous [[Royal Navy]] warships of different sizes such as {{HMS|Queen|1839|6}}, {{HMS|Odin|1846|6}}, {{HMS|Victor Emmanuel|1855|6}}, {{HMS|Sepoy|1856|6}} and the [[Conqueror class ship of the line|''Conqueror''-class ships of the line]].<ref name=RW>{{winfield}}</ref>  Several of these ships saw action during the [[Crimean War]] where the 68-pounder was used extensively during the [[Siege of Sevastopol (1854–1855)|Siege of Sevastopol]].<ref name=Winton112>Winton (2001), p. 112</ref>  Along with [[32-pounder smoothbore|32-pounders]] and [[68-Pounder Lancaster gun|Lancaster guns]] they were taken from their ship mountings and dragged up to siege batteries by the [[Naval Brigade]], from where they regularly bombarded Russian positions for the next year.<ref name=Winton112/>  The cannon was also fitted in large numbers to the [[Aetna class ironclad floating battery|''Aetna''-class ironclad floating batteries]], although these had little impact on the war.<ref name=RW/>

[[Image:Iron 64lb RML at Fort Nelson.JPG|thumb|right|A typical land based traversing carriage. This is actually a [[RML 64 pounder 71 cwt gun|64-pounder rifled muzzle loading]] cannon, displayed at [[Fort Nelson, Hampshire|Fort Nelson]].]]
Most notably the 68-pounder was fitted to the [[Warrior class battleship|''Warrior''-class battleships]] {{HMS|Warrior|1860|2}} and {{HMS|Black Prince|1861|2}}.  Originally it was intended to fit forty 68-pounders, primarily on one [[gun deck]], but this specification changed during their building and they were finally equipped with twenty-six 68-pounders (13 on each side).<ref name=Winton6>Winton (1987), p. 6</ref> Alongside these, the ships were equipped with new [[Rifled breech loader|rifled breech loading]] [[Armstrong gun]]s of two types; [[RBL 7 inch Armstrong gun|7 inch]] and [[RBL 40 pounder Armstrong gun|40 pounders]].<ref name=Winton6/>  Although the Armstrong guns represented a new direction in artillery, the breech loading mechanism meant that they were unable to withstand the explosion of a heavy cartridge. Smaller cartridge charges were therefore required and the gun's muzzle velocity suffered as a result.<ref name=Hogg37>Hogg, p. 37</ref> Ironically the Armstrong Guns were therefore incapable of penetrating the armour fitted to the ''Warrior''-class ships, while the 68-pounder (with its high muzzle velocity) could.<ref name=Hogg37/><ref>Cantwell, p. 31</ref>  As late as 1867 it was planned to fit the new [[Plover class gunvessel]]s with 68-pounders, but they were instead completed with a [[RML 7 inch gun]] and a [[RML 64 pounder 64 cwt gun]].<ref name=sag69>{{cite book |title=Send a Gunboat The Victorian Navy and Supremacy at Sea, 1854-1904 |last=Preston |first=Antony |authorlink=Antony Preston (naval historian)|coauthors=Major, John |year=2007 |publisher=Conway Maritime|isbn=9780851779232 |page=69}}</ref>

On land the 68-pounder was used extensively in British coastal defences constructed during the 1850s - notably at forts like [[fort Gomer|Gomer]] and [[Fort Elson|Elson]] defending  Portsmouth, and Forts [[Fort Victoria (Isle of Wight)|Victoria]], [[Fort Albert|Albert]] and [[Freshwater Redoubt]] defending the [[Needles Passage]].<ref>{{cite web|url=http://www.palmerstonforts.org.uk/rese.htm|title=The Palmerston Forts Society - Fortlog data sheets|accessdate=2010-05-08}}</ref>
The 1859 Royal Commission envisaged arming the [[Palmerston Forts|numerous new forts]] they proposed with the 68-pounder cannon and costed for them accordingly.<ref name=Hogg37/><ref name=Hogg25/>  The introduction of the Armstrong gun initially led many to think that weapon would be used instead, but whilst the forts were being built, the Armstrong gun's weaknesses were exposed and the military reverted to using muzzle loaded weapons.<ref name=Hogg37/>  However, the advantages of [[rifling]] and the Armstrong's [[wrought iron]] construction were retained, leading to a new design of artillery piece – [[Rifled_Muzzle_Loader#Rifled_muzzle_loaders|rifled muzzle loaders]].<ref name=Hogg37/>

==Conversion to rifled muzzle loader==
[[File:RML 80 pounder 5 ton gun Smiths Hill Fort Wollongong.jpg|thumb|left|<center>RML 80-pounder 5 ton gun at [[Smiths Hill Fort]], Wollongong, NSW, Australia</center>]]
The introduction of rifled muzzle loaders (also classed as RMLs) rendered smoothbore guns largely obsolete.<ref name=Hogg39>Hogg, p.39</ref>  However, the 68-pounder and other smoothbores still existed in large numbers and various attempts were made to adapt the guns to fire new projectiles.<ref name=Hogg37/><ref name=Hogg39/> Eventually Captain [[William Palliser]] patented a method of boring out the gun barrel and inserting a wrought iron rifled liner.<ref name=Hogg39/>  This allowed rifled shot and shells to be fired from old smoothbore cannon and experiments revealed that it made them even more powerful than they had been before.<ref>Hogg, p. 40</ref> Introduced in 1872, 68-pounders adapted in this way were classified as '''RML 68-pounder 5 ton''' or '''RML 80-pounder 5 ton''' and had a calibre of {{convert|6.3|in|cm|sigfig=4}}.  With a {{convert|10|lb|kg|abbr=on}} powder charge they could fire an {{convert|80|lb|kg|abbr=on}} projectile at a muzzle velocity of {{convert|1240|ft/s|m/s}}.<ref>{{cite book|first=John Fletcher|last=Owen|title=Treatise on Construction of Service Ordnance 1879|url=http://www.archive.org/details/treatiseonconst00owengoog|page=94|year=1879|isbn=}}</ref> They were deployed as coast defence and garrison artillery around the British Empire and remained in service until eventually declared obsolete in 1921.<ref>Hogg, p. 248</ref>

==See also==
{{Commonscat|ML 68 pounder 95 cwt gun}}
*[[68-Pounder Lancaster gun]] - a gun of the same weight and calibre, featuring an early design of rifling.

==References==
{{reflist|2}}

==Bibliography==
*{{cite book |first=Anthony |last=Cantwell |title=Fort Victoria: 1852–1969 |publisher=Isle of Wight County Council Cultural Services |year=1985 |isbn=0906328322}}
*{{cite book |last1=Hogg |first1=Ian |authorlink1=Ian V. Hogg |title= Coast Defences of England and Wales, 1856 – 1956|year=1974|origyear= |publisher=David & Charles |location=Vancouver |isbn= 0-7153-6353-0}}
*{{cite book|last=Lambert|first=Andrew|title=Warrior: Restoring the World's First Ironclad|year=1987|publisher=Conway|location=London|isbn=0-85177-411-3}}
*{{cite book |last1=Winton|first1=John |authorlink1= |title= Warrior, The First and the Last|year=1987|origyear= |publisher=Maritime Books |location=Cornwall |isbn= 0-907771-34-3}}
*{{cite book |last1=Winton|first1=John |authorlink1= |title= An Illustrated History of the Royal Navy|year=2001|origyear=First published in 2000 |publisher=Salamander Books |location=London|isbn= 1-84065-218-7}}

{{VictorianEraBritishNavalWeapons}}

[[Category:Naval guns of the United Kingdom]]
[[Category:Artillery of the United Kingdom]]
[[Category:Coastal artillery]]

[[Category:2Fix]]